Secondary lahars at Popocatepetl volcano: The Nexpayantla lahar of February 4th, 2010
Por:
Zaragoza G., Caballero-García L., Capra L., Nieto-Torres A.
Publicada:
1 ago 2020
Categoría:
Geology
Resumen:
Secondary lahars represent one of the major threats at active or
quiescent volcanoes. Therefore, it is important to stablish their
frequency, distribution, and triggering mechanism to define
hazard-scenarios.
In this work, an analysis of a lahar, that occurred on February 4th,
2010 in the Nexpayantla ravine, on northwestern sector of Popocatepetl
volcano is presented. A geomorphological and textural analysis coupled
with rain data and satellite imagery were used to determine its origin
and to delineate inundation areas. This lahar was triggered by a 100
mm/day precipitation and initiated as a stream flow, that transformed
into a debris flow, and ended as a stream flow. The transformation from
streamflow to debris flow was due to sediment entrainment by laminar
erosion and mass wasting processes. In contrast, its subsequent dilution
was favored by changes in channel geometry, the high wood content, and
the lack of fine sediment. Modelling of this lahar by numerical
simulations allowed to calculate a flow depth of up to 1.7 m. Satellite
imagery revealed that the deposit observed in the field represents only
68 % of the actual inundation area. Precipitation data indicates a
27-years return period for rains similar in magnitude to the one that
triggered this lahar. Further detailed studies of secondary lahars will
allow to better constrain hazard-scenarios at Popocatepetl volcano.
Filiaciones:
Zaragoza G.:
Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de México, Unidad de Posgrado, edificio D, primer piso, Cd. Universitaria, Coyoacán, Ciudad de México, Mexico
Caballero-García L.:
Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria, Av. Universidad 3000, Circuito Exterior S/N, Coyoacán, Ciudad de México, C.P. 04510, Mexico
Capra L.:
Centro de Geociencias, Universidad Nacional Autónoma de México, Blvd. Juriquilla No. 3001, Querétaro, Qro., 76230, Mexico
Nieto-Torres A.:
Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de México, Unidad de Posgrado, edificio D, primer piso, Cd. Universitaria, Coyoacán, Ciudad de México, Mexico
Gold, Bronze
|